With the increase of population base and the improvement of consumption level, the demand for primary energy is also rapidly increasing, and the energy gap faced will continue to increase. According to statistics from the World Energy Organization, the global primary energy consumption growth rate in 2018 was 2.9%, almost doubling compared to the average growth value of the previous decade, which is the fastest growth rate since 2010. Among them, China’s primary energy consumption growth rate reached 4.3%, the highest growth rate since 2012, and China accounted for 34% of the growth in energy demand. The contribution ratio of primary energy consumption growth in various countries is shown in the figure.
At present, China’s energy consumption is mainly based on non renewable energy sources such as oil, natural gas, and coal. According to the current consumption growth rate and energy storage capacity, the fossil energy stored on Earth will be depleted in a very short period of time. The extensive use of fossil fuels will inevitably lead to an increase in CO2 emissions, global climate change, inland drought The increase in desertification area and other changes in the ecological environment are also becoming increasingly significant. So solving the balance between energy demand and environmental protection is currently an urgent issue that humanity needs. With the development and research of renewable energy sources such as hydropower, geothermal, wind energy, and solar energy, their proportion in primary energy consumption is also increasing year by year.
In the new type of clean energy, solar energy is represented by its simple acquisition method, zero pollution, and high energy content.
(1) According to statistics, the power of solar fusion is about 3.75 * 1026W, which is equivalent to 1.3 * 1016 tons of standard coal generating heat. With the consumption in the universe, the energy reaching the Earth’s surface is also 1.73 * 1017W, which is 200000 times the current global electricity consumption.
(2) Solar energy is distributed on the global surface without geographical restrictions and has almost no usage cost, making it convenient and convenient.
Therefore, solar photovoltaic power generation is an important form of solar energy utilization and also one of the most promising power generation methods.
The distribution of solar energy is centered around the sun and radiates throughout the Earth’s surface. However, due to differences in climate conditions and latitude and altitude, the distribution of solar radiation on Earth is uneven. However, compared to other energy sources, solar energy can be used locally in most areas, which can balance the issue of uneven energy demand and storage. Solar photovoltaic power generation is a form of power generation that directly converts solar energy into electrical energy based on the photovoltaic effect of semiconductors. It is the mainstream form of solar power generation today. Compared with other clean energy generation technologies, solar power generation has the following characteristics:
(1) Zero pollution and zero emissions are green energy for sustainable development.
(2) It has a wide range of applications and flexible utilization methods, allowing for both grid connected and independent operation.
(3) It can serve as an uninterrupted power supply for power users to improve power quality and reliability.
(4) Power generation is not limited by geography and can be directly arranged in the load center, reducing the loss of energy transmission and grid pressure.
(5) The power generation efficiency remains constant.
(6) On site retrieval.
Due to the characteristics of solar photovoltaic power generation, its development speed is extremely fast, from early laboratory theory to 1% of the world’s total electricity production (as of 2015). Whether it is from being used as a supplementary energy source for conventional energy in the near future to replacing conventional energy with decentralized power sources to enter the electricity market in the long term, it has great significance.
China’s solar photovoltaic power generation started relatively late. In 2011, the global installed capacity of solar photovoltaic power generation was 70.49 GW, while China’s installed capacity was only 3.3 GW. However, the development speed of China’s solar photovoltaic power generation industry is extremely fast. By 2015, the global installed capacity of solar photovoltaic power generation had increased to 229.3 GW, and China’s installed capacity had increased to 43.53 GW. China has also built the Qinghai Gonghe Solar Photovoltaic Park Fujian Songxi Solar Photovoltaic Power Station, Zhejiang Cixi County Water Photovoltaic Complementary Power Station, Zhangbei Wind Solar Photovoltaic Complementary Power Station and other hundreds of MW level solar photovoltaic power stations. With the growth of the scale of solar photovoltaic power generation, the demand for solar cells is also increasing year by year. Since 2009, China’s production of solar cells has remained above 50% of global production, and the production of solar photovoltaic inverters has gradually occupied the main position of global production, injecting a strong boost into China’s solar photovoltaic industry.
Although China’s solar photovoltaic power generation industry has achieved certain results, compared with traditional fossil fuels, solar photovoltaic power generation still lacks economic competitiveness and market competitiveness. Large scale solar photovoltaic power generation projects are also mostly demonstration projects. Therefore, there is still great pressure on the development of solar photovoltaic power generation in China at present. During the 13th Five Year Plan period, China attaches great importance to the large-scale promotion of solar photovoltaic power generation during the energy transformation period. Under the influence of policies and situations, large and medium-sized enterprises have gradually driven the joint construction and development of small and medium-sized enterprises; The solar photovoltaic power generation industry is gradually shifting from centralized to a situation where centralized large-scale power generation and distributed small-scale power generation coexist, and will gradually replace traditional fossil energy power generation. On the other hand, China passed the Renewable Energy Law in 2005 to actively encourage individual users to install solar photovoltaic power generation equipment. In 2011, the National Development and Reform Commission issued a notice on improving the policy of solar photovoltaic power generation grid electricity prices and formulated a unified solar photovoltaic power generation grid electricity price in China. The cost and profit are recovered by selling the electricity generated, and the installation of rooftop power stations by users is promoted through government subsidies and other means, Spontaneous self use and the ability to sell excess electricity online, vigorously promoting the development and scale growth of China’s solar photovoltaic power generation industry.
As the most core equipment in the solar photovoltaic power generation industry, the inverter efficiency and capacity of solar photovoltaic inverters are closely related to the solar photovoltaic grid connected power generation industry. Solar photovoltaic grid connected inverters can be roughly divided into small capacity grid connected inverters with a capacity of 1-50kVA, commonly used in building BIPV and BAPV systems, as well as large capacity solar photovoltaic grid connected inverters with a capacity of over 200kVA, commonly used in large-scale photovoltaic power generation parks or super large-scale BIPV/BAPV systems. Before 2013, the development scale and research level of China’s solar photovoltaic grid connected inverters were relatively backward compared to foreign countries. More than 50% of the solar photovoltaic inverter market was occupied by German SMA company and Austrian Fronius company. With strong support for the solar photovoltaic industry in recent years in China, the production and market share of China’s solar photovoltaic inverters showed a rapid growth trend. As of 2018, Huawei Sunshine Power’s two Chinese solar photovoltaic inverter market shares are 22.0% and 25.0%, respectively, far exceeding the former giant SMA Company’s 15.0%. Large Chinese enterprises such as Shangneng Electric and TBEA are also growing rapidly. According to this development trend, Chinese solar photovoltaic inverters will play a crucial role in the global solar photovoltaic industry.